JPH04222493A - Motor driver and electric driver - Google Patents

Abstract

PURPOSE: To make linear the waveform of an excitating current, fed to the main winding of a motor drive apparatus. CONSTITUTION: A motor drive apparatus has a main winding and auxiliary windings. The main winding transfers an excitating current with a linear waveform, representing an excitating zone, and the auxiliary windings transfer first and second oppositely spiked pulses to each other, so that the respective pulses have instantaneous rise part portions correspondingly to the predetermined excitating zone. The rise portions of the first and second spiked pulses correspond respectively to the rise and fall portions of the excitating zone.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a variable magnetoresistive (VR) motor having a main winding in which the number of phases is n in the case of N≧1, and an auxiliary winding is closely attached to each phase. A unidirectional current is generated from a DC voltage source.
an electric drive with a power converter that supplies nalcurrent pulses;
system). The present invention provides an efficient and economical drive device which is characterized by its speed and/or torque controllability and by its ability to be combined with conventional components.

0002

BACKGROUND OF THE INVENTION Electric drives include a variable reluctance motor, a power converter that directs the flow of power to the main windings of the motor, and an adjustable DC voltage source to energize the motor. .

[0003] There are two types of VR motors, one of which has n built-in phases (N≧2).
at least one winding whose inductance increases as a result of movement of the rotor in one direction at any position of the rotor, and at least one winding whose inductance decreases as a result of movement of the rotor in that direction at any position of the rotor; The motor is a VR motor that can be reversibly rotated, or it can be rotated only in one direction and has n phases (however, N≧
1), and the inductance increases by movement of the rotor in a predetermined direction at any position of the rotor.
A dual-phase motor having two windings and each pair of poles being off-center as disclosed in U.S. Pat. No. 3,679,953 issued July 25, 1972. Either VR motor contains a rotor that is spiral. The phases of the motor constitute one or more groups, and each group includes at least one phase in which the inductance of the winding increases due to the movement of the rotor at any position on the rotor. Note that each phase belongs to only one group.

The power converter excites the phase at the rotor position where the inductance of the windings increases substantially due to rotor motion. The phase is energized by applying a DC voltage to its main winding, and the energization takes place at regular intervals. Excitation of the phase starts at a position of the rotor called the switch-on position. This position is the position where the inductance of the winding is approximately minimum. Also, the excitation of the phase is at the commutation point.
The rotor ends at a position called . This is the position where the inductance of the winding is below the maximum, the inductance of the windings of the other phases in the same group is the minimum, and the other phases are to be energized. When the power converter operates, the phases that make up one group are
Each phase is energized one after the other, but only one phase is energized at any instant, except near turning points, which may overlap depending on the switching technology. During the excitation period, the power converter supplies unidirectional current pulses to the main winding. The waveform of the supplied current pulse is linear, and this waveform is characterized by instantaneous changes in the current at the start and end of excitation. The instantaneous change in current in the main windings is reflected in each auxiliary winding.
There is a correlation with instantaneous changes in nding).

The basic characteristic of the current flowing through the auxiliary winding is that it is two short pulses of opposite direction. The current in the auxiliary winding changes instantaneously to a predetermined level at the beginning of each pulse and then slowly changes to zero.

[0006] The first pulse, at the beginning of excitation, is correlated with a rise in current in the main winding, producing a magnetic flux in the opposite direction to that produced by the main winding. The second pulse causes the current in the main winding to momentarily collapse.
e) to maintain the decreasing flux previously produced by the main winding.

[0007] The waveform described above is a basic feature of driving, and is a difference between the device of the present invention and known devices.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an electric motor drive device or system. An electric motor drive device includes a main winding that supplies an excitation current with a linear waveform. The waveforms have intervals depending on the excitation time. The motor drive further includes an auxiliary winding that forms a first spiked pulse and a second spiked pulse with opposite directions, each pulse having a substantially instantaneous duration corresponding to a predetermined excitation interval or interval. A leading edge is formed. In a preferred embodiment, the rising edge of the first spiked pulse corresponds to the rising edge of the corresponding excitation interval, and the rising edge of the second spiked pulse corresponds to the falling edge of the excitation interval.

[0009]

[Description of a preferred embodiment] The operating principle of a VR motor is based on a magnetomotive force (magnetomotive force) that generates magnetic force within a magnetic circuit that has two members, a highly permeable fixed member and a movable member.
tive force (MMF). The magnetic flux tends to minimize the MMF caused by reluctance due to the air gap between the members. 1 and 2 illustrate the phases of a typical VR motor.
se) operation. Here, a pair of main windings (11a) (11b) are attached to the inward protruding poles of the stator (1).
) and a pair of auxiliary windings (11ax) (11bx) are provided. Moreover, the movable member is a rotor (2) attached to a shaft (3).

The poles of the rotor may be symmetrical as shown, or they may have an off-center double spiral structure, but when the rotor rotates between two positions as shown in FIGS. The air gap between the stator and the rotor pole closest to the stator must be small. Further, during the rotation, a magnetic flux is excited by the main winding current, and the magnetic flux generates the torque that causes the rotation.

The auxiliary winding can either carry a return current to maintain the demagnetizing flux after the turning point, or, as will be described later, can be used as a secondary of a transformer with the main winding as the primary at the beginning of the excitation interval. Operate. As a result, the phase resultant MMF of the VR motor is the algebraic sum of the ampere winding of the main winding and the ampere winding of the auxiliary winding. As a result, the combined magnetic flux (resulta
nt magnetic flux) has a predetermined relationship with MMF, and is expressed by the following equation. N*I+Nx*Ix=(Magnetic resistance)*(Combined magnetic flux) Here, I is the current flowing from the + terminal of the main winding with N turns, and I
x is a current flowing from the + terminal of the auxiliary winding having Nx turns. The same relationship is also given by: N*If=(Magnetic Resistance)*(Combined Magnetic Flux) Here, If is the phase current given by If=I+(Nx/N)*Ix. It is well known that neither the combined magnetic flux nor the combined MMF changes instantaneously. Therefore, if the current in the auxiliary winding is then changed instantaneously so that the composite MMF does not change at that moment, it is possible to change the current in the main winding instantaneously.

When the magnetic flux F varies, an induced voltage E is produced between the terminals of the main winding and an induced voltage Ex is produced between the terminals of the auxiliary winding. Its value is respectively Faraday's law E=N*dF
/dt, and Ex=Nx*dF/dt.

As a result, the voltage ratio becomes E:Ex=N:Nx. If the magnetic permeability is constant and there is no current from the auxiliary winding, the voltage E across the main winding is given by the well-known equation: E=s(Li)/st Here, L is the inductance of the main winding, i is the current of the main winding, and the relationship regarding electromechanical energy conversion is given by the following equation as is well known. E=L(di/dt)+i(dL/dt) Energy can be delivered to the main winding of a phase and/or energy can be taken out of the auxiliary winding of a phase by respective circuit means. good. Regarding the operation of the phase, the main winding (11) and the auxiliary winding (
11x) will be explained as an example. The motor speed is approximately constant,
It is assumed that the load does not change. Although the speed change is caused by torque unevenness, it is considered to be small compared to the basic speed. The resistance of the winding is assumed to be negligible. Parts of circuit diagrams related to the operation of the phases are shown in FIGS. 7 and 8.

The circuit diagram shown in FIG. 7 includes a main winding (11), a series connection S1 and a DC voltage source. The anode terminal (13+) and the negative terminal (13-) are the connection points (nodes) with the external circuit, and are characterized by the fact that a substantially constant current can flow through the load connected between both terminals. . The load is only one main winding, and the main winding (11) is energized when switch S1 is connected. The current waveform is based on the back electromotive force (electromotive force) of the main winding.
It is hardly affected by unevenness of e force. Therefore, the MMF of the main winding is almost constant. The voltage between the voltage source terminals, when there is no current from the auxiliary winding, almost perfectly matches the waveform of the back electromotive force of the winding, allowing the motor current to be constant and the motor to be at a predetermined speed.

The switch means S1 may be a conventionally used solid state switch or a more traditional switch. A circuit diagram of the operation of the auxiliary winding is shown in FIG. The circuit diagram shown in Figure 8 includes an auxiliary winding (
11x), two sets of free rectifiers (11A) (11B) and (11C) (11D), and the anode terminal of the DC voltage source (
14+) and a negative terminal (14-).

The DC voltage source is a sink of current through the winding (11x) when one pair of rectifiers is biased forward. This voltage source is a dump source (du
mp source). If the voltage across the auxiliary winding is higher than the voltage across terminals (14+) (14-), one pair of rectifiers will be biased forward and current will begin to flow through the winding. When one pair is conductive, it depends on the polarity of the voltage between the auxiliary windings (11x). The magnitude of the voltage across terminals (14+) (14-) is such that power from the auxiliary winding is transferred only when the voltage across the main winding is greater than the maximum back emf of the winding at the rated motor speed. It is assumed that the A free rectifier in the auxiliary winding (
uncontrolled rectifiers) constitute a single-phase, full-wave rectifier and can easily be used as a single block rectifier.

Three patterns of energy flow characterize the operation of the phase. That is, when some or all of the power transferred to the main winding power is changed and returned to the supply by the auxiliary winding, when power is transferred to the main winding, and when the stored energy is transferred to the auxiliary winding When it is emitted by a line.

After the turning point, the current flowing from the + terminal of the auxiliary winding maintains a decreasing flux and the stored energy is transferred to the supply through a pair of rectifiers (11A) (11B). The polarity of the voltage in the main and auxiliary windings during the release of stored energy is shown in FIGS. 9 and 10. Also shown in FIG. 10 is the polarity of the forward biased rectifier pair.

As the voltage of the power source increases, the value of the return power also increases and the current pulses in the auxiliary winding become shorter.

When power is transferred to the main winding and the auxiliary winding is not carrying current, energy is extracted from the power source and converted to magnetic energy in the winding in a known manner. This reduction in the air gap between the stator and the rotor pole closest to the stator substantially reduces the reluctance and substantially increases the combined flux. During the magnetic flux rise, the polarity of the voltage in the main and auxiliary windings is shown in FIGS. 7 and 8, respectively. When the main winding current is constant and the auxiliary winding carries no current, the relationship for electromechanical energy conversion can be expressed as E=IdL/dt. Furthermore, by replacing dL/dt=(dL/dq)(dq/dt) and w=dq/dt, the relational expression E=I(
dL/dq)w is obtained. where L is the inductance of the main winding, q is the angular displacement of the rotor, and w is the angular velocity of the motor.

The instantaneous value of the main winding voltage at a given rotor position is, under the conditions described above, proportional to the angular velocity of the rotor. Therefore, while the rotor moves between two positions, the average voltage across the main winding is proportional to the angular velocity of the rotor. In the phase operation of the excitation section, the current in the main winding is approximately constant and no current flows in the auxiliary winding. Therefore, during excitation, the average voltage value across the terminals of the main winding is largely proportional to the motor speed.

As soon as a DC voltage is applied to the main winding,
Both the excited magnetic flux and the synthesized MMF disappear. When a direct voltage E is applied to the main winding and the auxiliary winding carries no current, the current in the main winding varies according to the energy conversion relationship, as in the known system. The switch-on position is determined such that the inductance of the winding is substantially minimum and changes little during current flow, giving the energy conversion relationship: E=L(di/dt) where E is the applied voltage, L is the inductance of the main winding, and i is the current of the main winding. The above relationship becomes valid when the current value (i+I) flows from the + terminal of the main winding, and when the current Ix flows to the + terminal of the auxiliary winding.
and the I part of the main winding becomes NI due to the current in the auxiliary winding.
-Compensation or correction so that NxIx=0
nsate). The composite MMF has dependence only on the part of the main winding current i. This is well known in transformers, where the primary and secondary currents are compensated for each other, while the voltage across the windings is maintained by the excitation current.

In the system according to the invention, the main windings are connected between the nodes of the circuit and current is forced through the connected windings. In the circuit diagram, a portion for forming magnetic flux is shown in FIG. The circuit diagram includes a DC voltage source Es and an inductor Ls. When the main winding (11) is connected between the terminals (13+) and (13-), the coil of the inductor is energized and the terminal (13
+). When there is no current from winding (11), the voltage across the winding of inductor Lx increases and tends to maintain MMF within the core of the inductor. The voltage polarity of the inductor is shown in parentheses in FIG. Ls
When the voltage applied to the main winding (11) increases momentarily, the voltage applied to the main winding (11) increases, and the voltage of the auxiliary winding (11x) similarly increases. The voltage across the terminals of the auxiliary winding increases until the pair of rectifiers (11C) (11D) is biased forward and current begins to flow through the auxiliary winding. The current in the auxiliary winding flows to the + terminal of the winding, creating a magnetic flux in the opposite direction to that created by the main winding, and the current in the main winding also rises.

The main winding and the auxiliary winding begin to act as a transformer. During a substation, the operation of the phase is determined by the constant current supplied to the main winding by the inductor, the voltage across the terminals of the auxiliary winding (which determines the voltage in the main winding), and the main winding current. It is determined by the rising magnetic flux excited by a part of the .

The main winding current as the primary current is the sum of two currents, the exciting current i and the current I, and Ni-NxIx=
It is corrected by the auxiliary winding current so that it becomes 0.

The excitation current maintains a magnetic flux that induces a back electromotive force (EMF) between the terminals of the main winding. It will tend to rise based on the above relationship and increase the total current flowing through the main winding. However, since the voltage applied to the inductor maintains a constant current, the voltage across the inductor will be slightly lower. The same applies to the voltages of the main winding and the auxiliary winding. This causes the rectifier to be biased forward in pairs, and the auxiliary winding current is delivered from the rectifier, immediately correcting the difference between the inductor current and the excitation current in the main winding. After the DC voltage is applied to the main winding, the excitation current is zero and the total current flowing through the main winding is compensated by the current in the auxiliary winding. The excitation current increases in response to the voltage in the main winding, and indeed increases in response to the voltage in the auxiliary winding and the inductance of the winding. As described above, the excitation current of the main winding is increased until the excitation current becomes equal to the inductor current. The main winding operates continuously with a constant current, and no power transforming is performed by the auxiliary winding. The phase current is equal to the excitation current. It seems reasonable to obtain the desired phase current before the rotor enters the region of rising inductance. This is because it supplies the maximum energy and is converted by the winding resulting in the predetermined current shown in FIG. By the above-described phase operation, any current value in the main winding can be created instantaneously.

The current flowing through the external inductor is assumed to be constant, although it varies depending on the difference between the average voltage value of the back EMF and the average value of the applied voltage. However, when the main winding current changes, a longer time is required than required to build the main winding current.

The phases of a group are successively excited by the same DC voltage source, each main winding being connected across the terminals of the voltage source by a respective switch connected in series. Only one switch is conductive at any given time. The waveform of the buck emf in the energized main winding is uneven, and in known systems, a constant current can only be obtained using a high speed current chopper. The ability to build up the current in the main winding instantaneously and the timing of the power converter ensures that the flow of current that excites the phases within a group is not interrupted. Therefore, the current can flow through the external inductor and/or other groups of phases can be excited by the same current. The additional inductance allows the excitation current to be approximately flattened. As in the case of DC shunt motors powered by a conventional controlled rectifier to an external inductor, the energizing so
The difference between the voltage at source) and the back emf of the energized winding is corrected.

This is the basic feature of the drive system according to the invention, which offers significant advantages compared to conventional systems.

The inductance of the additional inductor is:
Any high value is acceptable and the inductor can ensure that the current fluctuations are within predetermined limits. Therefore, the difference between the excitation source voltage and the back emf voltage can provide substantial advantages to the systems described above.

The DC power supply for exciting the windings of the VR motor may be any conventionally used power converter as long as it is a power converter used to excite a direct current (DC) motor.

[0032] VR motors can be energized over the entire speed range by such a source without overcurrent and are therefore very useful for low speed operation. VR
Motor speed and torque are related to excitation power supply voltage and current, respectively, relationships similar to those that define the operation of conventional DC motors. For this reason, the VR motor is excited by controlling the power supply, and either the speed feedback loop or the torque feedback loop is executed, or both the speed and torque feedback loops are executed, but this control is performed by exciting the DC motor. This is similar to power supply control. Electrical parameters relevant to power supply operation include motor speed, voltage across the power supply terminals,
and the excitation current of the motor windings. The excitation current flowing through any one of the main windings is detected by a single current sensor.

Constant currents are easier to handle with switching devices than peak currents, and this is especially easier when the switching device is a transistor. Since most of the parameters related to the back electromotive force are average values, the operating point of the motor is in a high magnetic saturation point region, and the back EMF is small. A saturated motor requires less kVA for the same kW output than an unsaturated one.

In a widely known VR drive device, when the back EMF decreases, a runaway potential state occurs, and the tendency toward spike current is caused by a commutative effect.
tation) or current chop. In the system of the present invention, the current is maintained under control by adjusting the power supply voltage that excites the motor. The control means for rendering the switch device electrically conductive therefore relates only to the rotational position sensor and is independent of the value of the current flowing through the winding. Therefore, the control means are simple.

Since most of the waveform of the back EMF does not affect the waveform of the excitation current, the construction of the VR motor is primarily concerned with the magnetization curve that determines the stored energy that has been converted in a predetermined manner. In the case of a three-phase VR motor, the phases constitute a group, as in the case of a two-phase VR motor. The circuit diagram is shown in FIG. The circuit includes main windings (11) (22) (33), switches S1, S2, S3 connected in series respectively, an adjustable power supply with terminals S+, S-, and an inductor Ls.

The power supply Es has an adjustable unidirectional voltage between the pair of output terminals.
Any known power source may be used as long as it can produce ltage). Current flows continuously between terminals S+ and S-. At a constant mechanical load, the change in average voltage across the power supply terminals is approximately proportional to the change in speed. The waveforms of the current flowing through the main winding are shown in FIGS. 17, 18 and 19, respectively, along with the respective inductor curves.

The waveform of the main winding is shown in FIG. 20, and the waveform of the auxiliary winding is shown in FIG. The illustrated current waveforms are the same for drive devices with different numbers of phases.

A rectifier is attached to each auxiliary winding, but the method of connecting the rectifier is different. Two examples are shown in FIGS. 14 and 16. Both circuits provide a flow of energy from an auxiliary winding to a DC voltage source. This voltage source is called a dump source,
It has a pair of terminals (anode terminal D+ and cathode terminal D-).

The circuit shown in FIG. 14 includes an auxiliary winding (11x
) (22x) (33x), and single blocks R1, R2
, R3 is included. Capacitor Cd is included when a suitable dump source is not at hand. This capacitor is called a dump capacitor. The illustrated circuit is suitable at disposal for sources which are characterized by a reversible energy flow in the voltage value between their terminals. This is the case if the motor is operated by the battery, otherwise the capacitor Cd acts as a dump source and the energy stored in the capacitor is recycled back to the motor. After rectification, i.e. switching on, current is carried immediately from the two auxiliary windings,
Both currents flow into the dump source. The circuits shown in FIGS. 13 and 14 constitute a control circuit for a three-phase VR motor. The circuits shown in FIGS. 13, 15, and 16 constitute control circuits for three single-phase VR motors. Figure 1
The circuit shown in 6 includes auxiliary windings (11x) (22x) (3
3x), each with a rectifier R1, R2, R3, after each rectification action any two of the three auxiliary windings.
The same current flows through both. Further, the voltage between the anode terminal D+ and the negative terminal D- is approximated as an algebraic sum of the absolute values of the voltages of the currents sent to the two auxiliary windings.

By the attached rectifiers R1, R2 and R3,
The current flows only through the auxiliary winding that captures the variable magnetic flux and is correlated with the current variation in the attached main winding. Otherwise, with this rectifier, the current flowing through the other auxiliary windings has no effect on the non-energized auxiliary windings.

The most basic features of the circuit shown in FIG.
When the same VR motor is provided with the circuit shown in Figure 14, the current flowing into the dump capacitor immediately after the rectification is
It is at the point where it is only half of the current flowing into the dump source. When the number of turns in the main winding is less than or equal to the number of turns in the auxiliary winding, the return current flowing into the dump capacitor is less than or equal to the excitation current flowing between terminals S+ and S- as shown in FIG. equal. Therefore, the current from the dump capacitor flows across both terminals S as shown in FIG.
+ and S- as part or all of the excitation current. The voltage of capacitor Cd is
maintained within a predetermined range.

When the return current flows through capacitor Cd, the voltage across the capacitor increases. When the voltage exceeds a predetermined value, the capacitor is discharged in the manner described above. The discharge circuit is a kind of step-down DC-DC voltage (SD) converter triggered by a dump capacitor Cd. Figure 15 shows the SD converter.
The converter has input terminals D+, D- and output terminals S+, S-. Input terminal D of SD converter
+ and D- are connected to the terminals D+ and D- of the dump source, and the output terminals S+ and S- of the SD converter, as shown in FIG.
are connected to terminals S+ and S- of the power supply shown in FIG. 13, respectively. When there is a demand to keep the current between the power supply terminals S+ and S- constant as shown in FIG. It disappears. As a result, the capacitor is used primarily for energy transfer and not for energy storage. Therefore, the electrolyte of the dump capacitor does not necessarily have to have a high voltage and capacitance rating.

[0043] This can be said to be an advantage of the present invention compared to conventional VR motor drive systems. because,
This is because the VR motor drive system does not require an electrolytic capacitor, which is essential in conventional systems.

Furthermore, the voltage of the electrolytic capacitor is electronically controlled and maintained at a predetermined voltage level, allowing the energy of one phase to be released quickly and the synthetic MMF of the other phase to be performed quickly.

[0045] The phases of the four-phase VR motor can constitute two groups. One group consists of windings (
11) (33), and the other group consists of windings (22
) (44). Ideal waveforms of the winding inductance are shown in FIGS. 25 to 28. Regardless of the position of the rotor, each group contains windings whose inductance increases substantially. Winding wire (11) (22)
(33) (44) are switches S1, S2, S3, S4
are connected in series with each other. Each main winding in a group is connected between the excitation terminals of the same pair by respective series switches, and the equivalent circuit between the terminals is the equivalent branch of the group (
equivalent branch). 2
As shown in FIG. 22, the two equivalent branches are the DC power source Es
is connected in series between the anode terminal S+ and the negative terminal S-. As the power source Es, any conventional power source may be used as long as it is capable of supplying an adjustable DC voltage between the pair of terminals.

When a current flows between the terminals and energizes the two groups of phases, the same current can flow through an additional external inductance. In this case, the two equivalent branches and the additional inductor are connected in series. Therefore,
Power converters for exciting the phases of a four-phase motor can take various forms. The circuit diagram shown in FIG.
This is just one example of a circuit for exciting the main windings of a phase motor. In this embodiment, two equivalent branches are connected in series between both terminals of the excitation power source. Figure 22
The operation of the circuit diagram shown in is determined by the magnitude of the power supply voltage, the algebraic sum of the back EMF of the two main windings that are excited, and the sum of the inductances of the two main windings carrying the same exciting current. In the VR motor with the winding inductance shown in Figures 25 to 28, the winding inductance increases linearly, and the algebraic sum of the back EMF of this motor is a curve with a flat top, which is ideal. It is ideal as a power source for producing flattened DC voltage. In the real world, motors with such winding inductance curves are usually different from those described above. However, the sum of the winding inductances carrying the excitation current, as well as the non-flat back EMF of the two series connected main windings, cause the motor to operate at substantially constant current. By connecting an additional inductor in series with other equivalent branches, the excitation current fluctuations can be reduced and the value of the inductance of the additional inductor can be increased so that the current fluctuations are within a predetermined range.

The circuit shown in FIG. 23 allows energy to flow from the auxiliary windings of a four-phase VR motor. The circuit includes auxiliary windings (11x) (22x) (33x) (44
x), each winding having a rectifier R1, R2, R3,
R4 is provided to transfer energy from the auxiliary winding to a dump source having an anode terminal D+ and a cathode terminal D-.

The circuit shown in FIG. 24 can perform the same operation as the circuit shown in FIG. The circuit includes an auxiliary winding (11x
)(22x)(33x)(44x) are included with rectifiers R1 and R2 corresponding to the two groups of phases, and further include the anode terminal D+ and the negative terminal D- of the dump source. The circuit shows a section related to the operation of one group, which includes an auxiliary winding (11x) (
33x), rectifiers R1, R2, and dump source terminal D+
, D- are included. This example shows how the windings of one group of phases can be connected with only one of the rectifiers with a dump source when the group consists of two phases.

When the number of turns of the main winding is equal to the number of turns of the auxiliary winding, the return current immediately after the rectification becomes equal to the current flowing between the terminals of the DC voltage, as shown in FIG.
It then decreases to zero. In this case, the voltage between the terminals of the auxiliary winding is smaller than or equal to the voltage between both terminals S+ and S- of the power source Es for exciting the main winding, as shown in FIG. Note that, as shown in FIG. 22, if the terminals S+ and S- of the power supply can also be the terminals D+ and D- of the dump source, the terminals S+ and S- shown in FIG.
This means that it can be directly connected to both terminals D+ and D- of the dump source, respectively. This is the same whether the circuit shown in FIG. 23 or the circuit shown in FIG. 24 is selected.

The fundamental advantage of the drive described above is that the supplied current is almost constant, without the need for capacitors for energy storage and without additional inductors. Driving without a capacitor reduces energy loss due to capacitor loss and energy transfer to and from the capacitor.

An end view of the switch means in a four-phase motor is shown in FIG. The switch means has an electrical insulator (5) attached to the motor shaft. The slip ring that performs the switching consists of a conductive part (6) (indicated by hatching) fixed to an insulator (5) and six non-conductive segments (7a) (7b) (7c) (7d) (7e). (
7f). Elements (5) and (6) together with segments (7a) to (7f) rotate with the rotor. Brush holders BH1, BH2, BH3 and BH4 are fixed on the stator housing and are electrically insulated. Brushes S1, S2, S3, and S4 are brushes used in conventional brush motors, and each brush is connected to a respective main winding. Each brush has a conductive segment (
6) in periodic contact with the brush S at any position on the rotor.
1 and S3, and one of the brushes S2 and S4,
Contact with the conductive segment (6). The angular position of each non-conductive segment and the position of each brush holder are selected such that each brush is in contact with a conductive area (6). On the other hand, the inductance of each main winding connected to the brush increases as the rotor rotates in a predetermined direction.

The brushes S1, S2, S3 and S4 are connected to one of the main windings (11), (22), (33) and (44) by wires B1, B2, B3 and B4, respectively, as shown in FIG.
connected to two terminals respectively. Windings (11) and (33)
The other side of the windings (22) and (44) is connected to the anode terminal of the DC voltage power supply for excitation, and the other side of the windings (22) and (44) is connected to the anode terminal of the DC voltage power source for excitation.
When connected to the negative terminal of the power supply as shown in the figure, the main winding (
Either one of 11) or (33) and the main winding (22)
or (44) excites the magnetic flux and generates torque, causing the illustrated motor to rotate clockwise.

As previously mentioned, the switching action of the slip ring eliminates the need for solid state switches. When both terminals of the dump source are connected directly to both terminals of the excitation source, as described above, and the rectifier attached to the auxiliary winding is installed in the stator housing, the 4-phase VR motor with switched slip ring It is connected to the excitation power supply by only two wires.

Although the present invention has been described in detail based on examples, the examples are merely illustrative, and a person skilled in the art will understand the scope of the present invention as defined in the claims. Various modifications can be made without departing from the above.

[Brief explanation of the drawing]

FIG. 1 is an end view of a VR motor, in which the section of the motor includes a pair of stator poles, a pair of main winding coils, a pair of auxiliary winding coils, and a rotor when the rotor is in the position shown. The pair of rotor poles closest to the stator poles are included, and the main and auxiliary windings are shown in cross section.

FIG. 2 is an end view of a VR motor, with the section of the motor having a pair of stator poles, a pair of main winding coils, a pair of auxiliary winding coils, and a rotor in the illustrated position; The pair of rotor poles closest to the stator poles are included, and the main and auxiliary windings are shown in cross section.

FIG. 3 is a diagram showing one winding (11) of a pair of main windings and one winding (11x) of a pair of auxiliary windings, from the + terminal of the main winding to The current flowing out creates a magnetic flux that overlaps the magnetic flux created by the current flowing out of the + terminal of the auxiliary winding.

FIG. 4 is a graph showing magnetization curves corresponding to rotor positions where the magnetic material is not saturated;

FIG. 5 is a graph showing a magnetization curve corresponding to a rotor position where the magnetic material is saturated, with hatching representing the amount of stored energy at a given rotor position when a current I is sent from the phase;

FIG. 6 is a graph showing the mechanical energy converted by the steady current delivery phase while the rotor moves between two positions, with the magnetization curves shown as a and b and the amount of energy converted shown as hatching; ing.

FIG. 7 is a diagram illustrating phase operation according to voltage polarity, with the current polarity shown in parentheses when DC voltage is applied to the main winding and no current is sent from the auxiliary winding. ing.

FIG. 8 is a diagram illustrating phase operation according to voltage polarity, with the current polarity shown in parentheses when a DC voltage is applied to the main winding and no current is sent from the auxiliary winding. ing.

FIG. 9 is a diagram illustrating the operation of the phases when the stored energy is discharged by the auxiliary winding.

FIG. 10 is a diagram illustrating the operation of the phases when the stored energy is discharged by the auxiliary winding.

FIG. 11 is a diagram illustrating the operation of the phases when power is transferred to the main winding and simultaneously exits from the auxiliary winding.

FIG. 12 is a diagram illustrating the operation of the phases when power is transferred to the main winding and simultaneously exits from the auxiliary winding.

FIG. 13 is a control circuit diagram for exciting the main winding of a three-phase VR motor.

FIG. 14 is an embodiment of a rectifier circuit that enables power transfer from an auxiliary winding of a three-phase VR motor.

FIG. 15 is an explanatory diagram of a DC voltage-DC voltage converter with terminals attached.

FIG. 16 is another embodiment of a rectifier circuit that enables power transfer from an auxiliary winding of a three-phase VR motor.

FIG. 17 is a waveform diagram of the current flowing through the main winding of the three-phase VR motor.

FIG. 18 is a waveform diagram of the current flowing through the main winding of the three-phase VR motor.

FIG. 19 is a waveform diagram of the current flowing through the main winding of the three-phase VR motor.

FIG. 20 is a waveform diagram of current flowing through the main winding and auxiliary winding of the VR motor.

FIG. 21 is a waveform diagram of current flowing through the main winding and auxiliary winding of the VR motor.

FIG. 22 is a control circuit diagram for exciting the main winding of a four-phase VR motor.

FIG. 23 is an example of a circuit that enables power transfer from an auxiliary winding of a four-phase VR motor.

FIG. 24 is another embodiment of a circuit that allows power transfer from the auxiliary winding of a four-phase VR motor.

FIG. 25 is a graph showing a waveform of a current flowing through a main winding of a four-phase VR motor and an inductance curve of the winding.

FIG. 26 is a graph showing a waveform of a current flowing through a main winding of a four-phase VR motor and an inductance curve of the winding.

FIG. 27 is a graph showing a waveform of a current flowing through a main winding of a four-phase VR motor and an inductance curve of the winding.

FIG. 28 is a graph showing a waveform of a current flowing through a main winding of a four-phase VR motor and an inductance curve of the winding.

FIG. 29 is an end view of a slip ring functioning as a switch means for exciting the main windings of a four-phase motor.

[Explanation of symbols]

(2) Rotor (3) Axis

Claims (5)

[Claims] Claim 1: A main winding and an auxiliary winding, wherein the main winding transmits an excitation current with a linear waveform representing an excitation section, and the auxiliary winding transmits a first spiked pulse and a second spiked pulse in opposite directions. An electric motor drive device configured to transmit pulses, each pulse having an instantaneous rise portion corresponding to a predetermined excitation interval. Claim 2: The rising portion of the first spiked pulse is
2. The apparatus of claim 1, wherein the rising part of the second spiked pulse corresponds to a rising part of the excitation interval and the rising part of the second spiked pulse corresponds to a falling part of the excitation interval. 3. The number of phases is n (where n is greater than or equal to 1), and each phase includes a main winding and an auxiliary winding magnetically coupled to the main winding. a variable reluctance motor, the motor further having at least one phase in which movement of the rotor in one direction increases the inductance of the windings at any position of the rotor, the motor having one or two phases; When forming the above groups, each group includes at least one phase in which the inductance of the winding increases due to movement of the rotor in a predetermined direction, and each phase belongs to only one group. a resistive motor and an adjustable DC voltage power supply provided to excite the motor and provide a unipolar voltage across its terminals, between which there are equivalent branches of the group and an external inductor connected in series; or two equivalent branches of each group connected in series with each other, or two equivalent branches of each group further connected in series with an external inductor. Circuit means for applying a unipolar excitation voltage to each main winding, including a direct current voltage source and respective switch means connected in series with the main winding, wherein each group of phases is connected between a pair of terminals. is connected to each main winding of the group and the respective switch means, where the equivalent circuit between the terminals shall be referred to as the equivalent branch of the group, and the control means controls the phases of one group one by one and optionally The switching means are controlled in such a way that only one of them is conductive at a time of and circuit means for terminating at a rotor position in which other phases of the same group are energized at a substantially minimum value. 4. When a DC voltage source is a sink of current transmitted from a corresponding auxiliary winding, said source is called a dump source and is provided with a pair of terminals, an anode and a cathode, and the circuit means are respectively coupled to each auxiliary winding to enable a flow of energy from the auxiliary winding to the corresponding dump source, and where the circuit means includes two pairs of free rectifiers, the first pair of rectifiers is The cathodes are connected to the anode terminals of the corresponding dump sources, the anodes of which are connected to the terminals of the auxiliary windings, and the anodes of the second pair of rectifiers are connected to the cathode terminals of the corresponding dump sources, and the anodes of the second pair of rectifiers are connected to the cathode terminals of the corresponding dump sources, respectively. 3. The cathodes are respectively connected to terminals of the auxiliary windings.
The device described in. [Claim 5] A group consisting of a plurality of phases is:
Each group contains only two phases and further contains a DC voltage power supply, which is a sink for the current transferred from the auxiliary windings of the phases in one group, the power supply being called a dump source; A pair of anode and cathode terminals are provided, and circuit means is coupled to a pair of auxiliary windings of the phases within a group to enable flow of energy from the auxiliary windings to a corresponding dump source;
When a pair of auxiliary windings are connected in series, the current flowing through the windings forms a magnetic flux in one winding that is opposite in direction to the magnetic flux created by the excitation current flowing through the main winding, and If the terminals of a winding are not connected in series with other windings and are called free terminals, and the free terminals are each connected to two pairs of free rectifiers, the first pair of rectifiers The cathodes are connected to the anode terminals of the corresponding dump sources, the anodes of which are respectively connected to said terminals, and the anodes of the second pair of rectifiers are connected to the cathode terminals of the corresponding dump sources, and the cathodes of the second pair of rectifiers are connected to the cathode terminals of the corresponding dump sources. 4. A device according to claim 3, each connected to a terminal of the winding.